High-Speed Metal–Germanium–Metal Configured PIN-Like Ge-Photodetector Under Photovoltaic Mode and With Dopant-Segregated Schottky-Contact Engineering

In this letter, we present a high-speed metal- germanium-metal configured Ge-photodetectors (MGM-PDs) under photovoltaic mode (i.e., 0-V operation). The metal contacts are engineered by an asymmetrical (i.e., boron and arsenic) dopant-segregation scheme on Schottky-contacts to suppress the dark current, and are with scaled spacing ( ~ 0.8 mum). The MGM-PD (with ~ 300-nm-thick Ge) is integrated on a silicon-on-isolator waveguide with complementary metal-oxide-semiconductor field effect transistor compatible process. For lambda = 1550 nm, under 0-V bias, the devices illustrate a reasonable responsivity ~ 0.17 A/W and a fast pulse response of 18 ps.